Effects of Acetylcholine, Adrenalin and other Drugs on the Action Current of Frog's Skin

Effects of various pharmaca such as atropine, adrenalin, acetylcholine etc. on action currents of frog's skin were investigated in order to contribute something to the problem of chemical transmission at endings of secretory nerve of the skin. 1. Atropine either abolishes or depresses action currents in higher concentrations than 0.0001%. 2. Adrenalin acts in the same gray, and the critical concentnations. is about 0.10001%. 3. Acetylcholine depresses action currents in higher concentrations such as above 0.1%. but increases them above normal in middle and lower concentrations. 4. Pilocarpinc acts in the same way as acetylcholine. The only difference consists in that its action is not inhibited by 0.01% atropine, while acetylcholine is entirely ineffective at preparations paralysed by 0.01% atropine. 5. Though adrenalin is able to abolish action currents, it is unable to inhibit the increasing action of acetyicholine and pilocarpine.